The present invention is concerned with a hydraulic transmission device and in particular with a hydrodynamic adjustable-speed fluid transmission.
Various types of torque converters, hydraulic couplings and fluid transmission devices of the type which employ an impeller or pump driven by a power source to circulate a transmission fluid to an output turbine which drives an output shaft or the like are, of course, known in the art. The following U.S. Patents describe typical prior art expedients.
Stump et al U.S.Pat. No. 2,929,214 shows a hydrodynamic torque converter and brake in which an impeller is mounted on a driving shaft 13 and a turbine 11 is mounted on a driven shaft 14. In operation, the driving shaft 13 causes the impeller 10 to act as a pump which circulates the liquid within the housing and transmits energy via turbine 11 to driven shaft 14. As disclosed in the paragraph bridging columns 2 and 3 of the patent, the position of vaned portions 19 of the vanes 15 may be adjusted about studs 20 t produce the desired braking couple between the elements.
Kelley U.S. Pat. No. 2,999,569 discloses a hydrodynamic torque converter which comprises a pump P, a first turbine Tl, a second turbine T2, and a stator or reaction member R. As described beginning at line 46 of column 3, rotation of a fly wheel 12 drives pump P which circulates liquid to rotate turbine T1 and thereby drive turbine T2 through a planetary gear system. Beginning at line 50 of column 4, under the heading "Controllable Stator", means to permit a change in the stator blade orientation between the low angle and high angle positions is described. See also the paragraph in column 7 under the heading "Stator Blade Contour".
Walker et al U.S. Pat. No. 3,466,869 discloses a hydrodynamic torque converter comprising a pump and turbines comprising first blades 13 and second blades 15 with bladed stator elements disposed in the fluid flow path. The second stator has blades 51 mounted on pins 43 and disposed between the second turbine blades 15 and the pump 7. Starting at column 3, line 52 there is described pivoting movement of stator blades 51 between high and low angular positions relative to the center line of the converter.
Wirz U.S. Pat. No. 2,670,602 discloses a rotary turbine type hydraulic coupling in which a driving shaft 7 carries an impeller 8 and a driven shaft 15 is splined to a sleeve 16 which carries a rotor 18. As described at column 3, lines 20-30, as the torque transmitted to shaft 15 increases, rotor 18 travels on sleeve 16 backing away and thereby decoupling from the impeller 8. A funnel-like fluid collector 28 collects liquid discharged through openings 13 and reintroduces it into an impeller chamber through annular openings 14.
Lewis U.S. Pat. No. 2,718,944 discloses a rotary hydraulic coupling comprising a drive impeller and a driven turbine member having an interfitting vane construction comprising members which are movable relative to each other thereby to effectuate selectively a forward and reverse drive. As described in the paragraphs bridging columns 2 and 3 of the patent, movement of turbine 16 outwardly reverses the flow with respect to vanes 27 and 28 in order to accomplish reverse drive.